1. Field of the Invention
The invention relates to a startup-time control apparatus and a stop-time control apparatus in an internal combustion engine in which fuel is injected into a combustion chamber, and also relates to control methods of the apparatuses, and a record medium storing the control methods.
2. Description of the Related Art
A known related-art technology is an automatic stop-start apparatus that automatically stops an internal combustion engine when the vehicle is in a stopped state, for example, for a traffic signal or the like, and that automatically starts up the engine for a start of the vehicle upon an operation for a vehicle run, for the purpose of improving fuel economy and reducing emissions. In a known system, the above-described automatic stop-start apparatus is combined with a direct-injection type gasoline engine, that is, an internal combustion engine in which fuel is injected into a combustion chamber (Japanese Patent Application Laid-Open No. 2000-328979).
When an internal combustion engine stops operating, the water pump driven by the engine also stops. Therefore, after a stop of operation of the engine, the temperature inside the combustion chambers does not immediately fall, but temporarily remains high because the cooling by the water pump is not performed. In a construction where an automatic stop-start apparatus as described above is adopted, the automatic stop duration from an automatic stop to an automatic start tends to be considerably shorter than a manual stop duration. Therefore, in many cases, the temperature in the combustion chambers is high at the time of an automatic start.
If a direct-injection type internal combustion engine is started while the combustion chamber temperature is high, fuel is injected from fuel injection valves into high-temperature combustion chambers simultaneously with the cranking. Therefore, there is a danger of pre-ignition.
The problem of pre-ignition is not limited to the case of an automatic startup performed by an automatic stop-start apparatus, but may also occur at the time of a manual engine startup operation performed by a driver if the duration from the stop to the startup of the engine is short so that the combustion chamber temperature remains high.